Training your Jack Russell while it's a puppy is an effective way to help ingrain commands and actions while it is still most impressionable. Like most mammals, Jack Russells are in their mentally formative stage when they are young. Sitting, coming, and lying down are some of the basic things you can train your Jack Russell puppy to do. Bear in mind that repetition and consistency are the keys to successful training.
Instructions
Teach your puppy to sit: Associate the reward of a treat with the action of sitting down. Have your puppy stand near you and place a treat in your hand. Command the dog to "sit" while you gently push its rear end down to the ground. If necessary, move its rear legs so that it will begin to sit. When your dog has successfully sat down, reward it with a treat. Repeat this several times over the course of one sitting and practice the command each day to ensure that your puppy remembers the training.
Teach your puppy to lie down: Associate the movement of lying down with the reward of a dog treat. In order for this to work, you must first master the sitting command with your dog. Tell your dog to sit down. Then command it to "lie down." Facilitate the movement of its legs so that it lies down if you need to and reward it with a treat. Eventually, you can skip the command to sit and just issue the "lie down" command.
Place the leash on your Jack Russell's collar and stand a few feet away from it with a dog treat in your hand. Command it to "come" and make playful and friendly motions with your hands that illustrate a movement in toward you. If the dog comes to you on its own, reward it with a treat and continue to practice it. If your dog is not sure what to do when you command it to "come," pull it toward you using the leash while giving positive and friendly encouragement. When your puppy has come to you, be sure to reward it with a treat.